Ordovician and Silurian igneous rocks and orthogeneisses in the Catalonian Coastel Ranges

Abstract

These rocks exhibit calc-alkaline affinities and may have originated by partial melting of the crust in a post-collision, anorogenic setting. Orthogneisses derived from biotite-bearing leucogranites occur within aprobably cambrian heterogeneous series. Petrological and geochemical features suggest that they might be genetically related to the ordovician vulcanites. Basic sills and volcanoclastic rocks occur intercalated within a mainly pelitic formation in the lower part of the Silurian sequence. The silurian igneous rocks are alkali basalts and may reflect an extensional regime.